;solution for euler 15

(defun goto00 (x y)
	(let ((ret 0))
		(when (and (= x 0) (= y 0)) (return-from goto00 1))
		(when (> x 0) (incf ret (goto00 (- x 1) y)))
		(when (> y 0) (incf ret (goto00 x (- y 1))))
		(return-from goto00 ret)))
		
(defun solve-euler15 ()
	(format t "Euler 15:~a" (goto00 20 20)))